heat issue with growing in soil in pots on hot balcony

M

Mike_B

Member
Hello everyone, beginner cannabis grower here :)

My situation is that I'm growing in pots on a balcony and recently it's been really hot, right now we're in a bad heatwave with the sun relentlessly scorching every single day. Temps outside get up to 35C/95F but to make matters worse the balcony I'm growing my plants on is "inside" the house (it's not sticking out from the exterior walls) so on days with no wind there is a pocket of heat being accumulated, plus the balcony is so much insulated (white walls, white window blinds down during most of the day) that it's almost an oven sometimes. Temps can easily get up to 43C/110F.

I already got some excellent advice about insulating my pots using mulch and wrapping the pots in a reflective material, but my bigger concern is prolonged ambient heat. Let's say for example I have my plants on my balcony and I manage to keep the pots in the shade, but the sun hits the balcony for 9 hours straight causing the pots even in the shade to be surrounded in 43C/110F for that long time. I image eventually equilibrium sets in and the roots will also reach that temp.

What is the maximum temp you guys would allow the roots to be exposed to? And how would you solve this intense heat problem in my particular case?

Moving the plants inside during the day would not really be an option I reckon since drawing the window blinds on hot days means the room is dark and the plants would not receive any light except for a regular 5W LED bulb on the ceiling and I can't do growing lights inside. The sun is all I have :)

I'm growing AK420 Auto and BCN Critical XXL Auto.
 
  • Like
Reactions: ISK
ISK

ISK

Well-Known Member
I wouldn't worry about them unless your plants are showing heat stress.

If they start drooping and looking stressed, then move them inside for a few hours until the temps cool a bit.

It's better to have them in the house (with blinds shut) than to leave them outside stressed....but if they handle the heat, leave them outside.
 
MICHI-CAN

MICHI-CAN

Well-Known Member
Mike_B said:
Hello everyone, beginner cannabis grower here :)

My situation is that I'm growing in pots on a balcony and recently it's been really hot, right now we're in a bad heatwave with the sun relentlessly scorching every single day. Temps outside get up to 35C/95F but to make matters worse the balcony I'm growing my plants on is "inside" the house (it's not sticking out from the exterior walls) so on days with no wind there is a pocket of heat being accumulated, plus the balcony is so much insulated (white walls, white window blinds down during most of the day) that it's almost an oven sometimes. Temps can easily get up to 43C/110F.

I already got some excellent advice about insulating my pots using mulch and wrapping the pots in a reflective material, but my bigger concern is prolonged ambient heat. Let's say for example I have my plants on my balcony and I manage to keep the pots in the shade, but the sun hits the balcony for 9 hours straight causing the pots even in the shade to be surrounded in 43C/110F for that long time. I image eventually equilibrium sets in and the roots will also reach that temp.

What is the maximum temp you guys would allow the roots to be exposed to? And how would you solve this intense heat problem in my particular case?

Moving the plants inside during the day would not really be an option I reckon since drawing the window blinds on hot days means the room is dark and the plants would not receive any light except for a regular 5W LED bulb on the ceiling and I can't do growing lights inside. The sun is all I have :)

I'm growing AK420 Auto and BCN Critical XXL Auto.
Click to expand...
Wet the balcony down as needed. Assuming cement or equivalent. Will reduce ambient and residual temps.
 
ProPheT 216

ProPheT 216

Well-Known Member
Hotter means increased water up take and increased evaporation out of the soil. You certainly will have to water more, so make the water as cold as you can. Even if you have to freeze 2 liters and sticking them in your bucket while you mix nutrients
 
MICHI-CAN

MICHI-CAN

Well-Known Member
ProPheT 216 said:
Hotter means increased water up take and increased evaporation out of the soil. You certainly will have to water more, so make the water as cold as you can. Even if you have to freeze 2 liters and sticking them in your bucket while you mix nutrients
Click to expand...
I object. Is like defrosting glass with hot water. The shock.
 
ProPheT 216

ProPheT 216

Well-Known Member
2 liters don't get anything that cold, but will help get that water from 75 f + to 55f momentarily and cool the pots, and soil will bring that 55 right back to 62 immediately
 
MICHI-CAN

MICHI-CAN

Well-Known Member
ProPheT 216 said:
I dwc and pots are about 72 all week, but when I refill water is much colder. No harm done ever
Click to expand...
I do 2-3 gallon pots of organic soil. Tap is 50-60F. Causes a wilt on days over 80F.

And you are filling a reservoir. Not directly watering.
 
obijohn

obijohn

Well-Known Member
I use those black nursery pots. After feeling how hot they get being in direct 100dg + sun, I spray painted them flat white, also have wrapped some with flat white posterboard. Helps the heat a lot.
 
Wizzlebiz

Wizzlebiz

Well-Known Member
1 use a sun screen above the plants.
2 add straw to the top of pot.
3 keep them hydrated
4 add a riser under the pot. Put the rise into a clear plastic pan below with white rocks and water in said pan. Make sure riser is high enough where pot is not in said water.
As the water evaporates it will cool the temps around the plants by a couple of degrees.
 
  • Like
Reactions: ISK
T

T.H.Cammo

Well-Known Member
I know from personal experience that high 90's - "100-teens" won't kill your plants. It will just slow down the growing process. I grew a dozen or so plants outside in that heat (high 90's - over 110 f. every fuckin' day) for a whole season. And, at harvest, none of them were over about 24" (well, maybe 30" or so - it was a long time ago). I was growing in 5 gal. plastic buckets in full direct sunlight on an asphalt driveway.

Hang in there!
 
C

CaptainLucky

Member
Mike_B said:
Hello everyone, beginner cannabis grower here :)

My situation is that I'm growing in pots on a balcony and recently it's been really hot, right now we're in a bad heatwave with the sun relentlessly scorching every single day. Temps outside get up to 35C/95F but to make matters worse the balcony I'm growing my plants on is "inside" the house (it's not sticking out from the exterior walls) so on days with no wind there is a pocket of heat being accumulated, plus the balcony is so much insulated (white walls, white window blinds down during most of the day) that it's almost an oven sometimes. Temps can easily get up to 43C/110F.

I already got some excellent advice about insulating my pots using mulch and wrapping the pots in a reflective material, but my bigger concern is prolonged ambient heat. Let's say for example I have my plants on my balcony and I manage to keep the pots in the shade, but the sun hits the balcony for 9 hours straight causing the pots even in the shade to be surrounded in 43C/110F for that long time. I image eventually equilibrium sets in and the roots will also reach that temp.

What is the maximum temp you guys would allow the roots to be exposed to? And how would you solve this intense heat problem in my particular case?

Moving the plants inside during the day would not really be an option I reckon since drawing the window blinds on hot days means the room is dark and the plants would not receive any light except for a regular 5W LED bulb on the ceiling and I can't do growing lights inside. The sun is all I have :)

I'm growing AK420 Auto and BCN Critical XXL Auto.
Click to expand...
I was getting advice on the same problem,it’s been 80s-90s here and the bro I was getting advice from lived in NW desert growing outdoors daytime temp 115 with 50mph wind gusts. He told me that it’s just getting them acclimated.
 
xtsho

xtsho

Well-Known Member
Budz.Bunny said:
I thought this was interesting


View attachment 5167641
View attachment 5167640


I'd probably only use it during veg cycles tho
Click to expand...
There is no scientific evidence to back up those marketing claims. The castor bean plant is where ricin comes from and is one of the most toxic substances on earth. The castor bean oil itself does not contain any ricin. That comes from the husks and outer shell which is removed before pressing the oil.

It's also used as a laxative and deterrent for pest like gophers and moles. It's not going to perform the claims made by the manufacturer. I can't believe the things companies can sell and make all these claims. But apparently people buy it. A couple tablespoons at most of castor bean oil in a quart of water for $25. You can buy a gallon of castor bean oil for $35.
 
PadawanWarrior

PadawanWarrior

Well-Known Member
xtsho said:
There is no scientific evidence to back up those marketing claims. The castor bean plant is where ricin comes from and is one of the most toxic substances on earth. The castor bean oil itself does not contain any ricin. That comes from the husks and outer shell which is removed before pressing the oil.

It's also used as a laxative and deterrent for pest like gophers and moles. It's not going to perform the claims made by the manufacturer. I can't believe the things companies can sell and make all these claims. But apparently people buy it. A couple tablespoons at most of castor bean oil in a quart of water for $25. You can buy a gallon of castor bean oil for $35.
Click to expand...
My wife drank castor oil once to try to help induce labor, lol. She went into labor alright. She was delivering Mr. Hanky over and over again, :lol:
 
You must log in or register to reply here.
Top